<?php
$advert = array(); 
$advert[0] = '<a href="http://www.hjerteforeningen.dk/" target="_blank"><img src="oc-content/themes/twitter/v35extra/imgrightsiderotor01/hjerteforeningen.jpg" alt="" width="251" height="100" /></a>';
shuffle($advert); 
echo $advert[0];
?>